Here are some tips off my website:
1.Clean out computer history everyweek.
2.Clean out the cookies folder Start+run+cookies everyweek.
3.Defragment your computer everyweek.
4. Disk cleanup your computer every week.
5. Run a virus scan every 2 days.
6. Check for updates everyday.
7.Clean out unwanted files everymonth.
8.Do a system backup twice a week.
9.Clean the dust out of your computer every month.
10.Most important remember to switch it off,if not using!